The disclosure relates to a hydraulic adjusting device.
An adjusting device of this type has an adjusting cylinder with a piston or with a piston arrangement with two piston surfaces which are effective in opposite directions, wherein a first working space is delimited via a first of the piston surfaces and a second working space is delimited via a second of the piston surfaces. The adjusting cylinder which is thereby configured to be double-acting therefore has an adjusting direction and a resetting direction. In a working operation, the two working spaces are acted upon with an in particular incompressible or hydrostatic working pressure medium. An adjusting device of this type is used, for example, for adjusting a rotor blade of a wind energy installation or for adjusting a valve in a cooling circuit of a different energy installation.
In order to ensure an adjustment, for example, of the rotor blade even in a special operation, in particular in an emergency or emergency moving operation, the adjusting device additionally has a pressure medium accumulator which, for this purpose, is connectable to the adjusting cylinder. An adjusting device of this type is shown, for example, in the document DE 101 22 858 A1.
However, a disadvantage of the solution shown there is that the same working space is used both for carrying out the working function of the adjusting device and for carrying out the special function or emergency moving function. A pressure medium circuit for the working operation is therefore not separate from the pressure medium circuit of the special operation, and this can have a disadvantageous effect on fail-safety in the event of the special operation. A further disadvantage of the solution shown is that two separate cylinders are provided for carrying out the two functions, which constitutes a high outlay in terms of apparatus. Even if the spring accumulator shown in the solution is replaced by a gas-loaded hydraulic accumulator, the adjusting device shown also continues to have such a high overall weight that it is not very suitable in particular for use as an adjusting device for a wind energy installation in which a low weight is significant.
By contrast, the disclosure is based on the object of providing a hydraulic adjusting device which is simplified in terms of apparatus.